Wheel drive for airplanes



Nov. 30, 1943. P; A, DOWNEY I 2,335,393

WHEEL DRIVE FOR AIRPLANES Filed Jan. 29, 1942 2 Sheets-Sheet l Nov. 30,1943. p, DOWNEY 2,335,398

WHEEL DRIVE FOR AIRPLANES Filed Jan.- 29, 1942 2 Sheets-Sheet 2 I uzeizior PA ()JL A. D0 W/VEY,

Patented Nov. 30, 1943 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates to improvements in wheel drives tor the landinggear wheels of airplanes, the primary object in view being to provide asimply constructed, built-in, compact motor drive for variably rotatingsuch wheels prior to landing at a speed corresponding to the speed oftravel of the plane at the instant of landing, so as to reduce shock andjar incident to landing operations and obviate wear on the wheel tires.

To the accomplishment of the above, and subordinate objects presentlyappearing, a preferred embodiment of my invention has been illustratedin the accompanying drawings, set forth in detail in the succeedingdescription, and defined in the claims appended hereto.

In said drawings:

Figure l is a fragmentary view in side elevation of a portion of anairplane landing gear including a wheel embodying my improvements,

Figure 2 is a view in side elevation oi said wheel with the front coverplate removed,

Figure 3 is a view in vertical transverse section taken on the line 33of Figure 2 and drawn to an enlarged scale, and

Figure 4 is a diagrammatic view oi the circuit.

Reference being had to the drawings by numerals, in accordance with myinvention a landing gear wheel I of the disc type is provided includinga rim 2 equipped with edge retaining flanges 3 for a pneumatic tire 4, aback plate forming together with said rim a circular, open front chamberI in the wheel, and a cap-type closure plate 1 for said chamber adaptedto be set in to the front edge of the rim 2 and to be secured to saidedge by bolts 8.

The back plate 5 includes a hub portion 8 having set into the same fromthe inner side thereof an anti-friction bearing assembly I. preferablyof the tapered roller bearing type. The front plate 1 has suitablymounted therein, as by the spider ll, an anti-friction bearing assemblyl2. Both bearing assemblies l and I2, as will be understood, are axiallyaligned in the axis of the wheel l.

The described wheel I is rotatably mounted on a tubular spindle I! fixedin and extending from one leg ll of the landing gear, said spindle beingjournaled in the bearing assemblies l0, l2 and having a closedexternally threaded outer end. Washer l and'nut IS on said outer end ofthe spindle l3 secure the latter in the bearing assemblies l0 and I2. Adetachable cap 1 on the closure'plate I, preferably threaded thereon,

provides for access to the interior of said plate.

Within the chamber 6 is a plurality of electro-magnetlc field coil unitsl1 secured in any suitable manner to'the rim 2 to extend radiallytherefrom in equidistantly spaced relation around the chamber, therebeing preferably four of such units as shown. The said field units H, aswill be clear, are designed. to he revolved with the wheel around theusual armature l8 fixed in any suitable manner on the spindle i3 andprovided on the outer side thereof with the usual.

commutator ring l9 surrounding the spindle i3 concentrically thereof,the commutator ring being fixed as will be understood.

Alongside the commutator ring l9 and suitably fixed on the spindle i3 isa sleeve 20 of insulationconcentric to the spindle and having embeddedin the periphery thereof a pair of laterally spaced inner and outercollector rings 2|, 22 of any suitable conductive material.

A pair of end thrust ball bearings 23; 24 are interposed between thearmature l9 and bearing assembly l3 and between the sleeve 20 and thebearing assembly l2.

Surrounding the commutator ring l8, and the sleeve 20 and collectorrings El, 22, in concentric spaced relation thereto, is an annular brushcarrier 25 of insulation material mounted on the rim 2 of the wheel tobe revolved therewith. Preferably the mounting for the brush carrier 2!comprises a pair of diametrically opposite arms 28 extendingtherefrom'and bolted, as at 21, to internal lugs 28 on said rim 2.

A pair of plug-like brushes 29 are suitably mounted in the brush carrier25 in diametrically opposite relation to slidably extend radiallythrough said carrier and bear against the commutator ring l9, saidbrushes being spring pressed inwardly by leaf springs 30 against said.ring. A similar, diametrically arranged pair of spring pressed brushes3|, 32 are provided in the brush carrier 25 to bear against the innerand outer collector rings 2|, 22, respectively, in degree angularrelation to the brushes 29.

Referring now more particularly to Figure 4, preferably the describedfield is designed to be energized from a source of power in the airplanesuch as a battery 23 and under control of a rheostat. The control arm Iof the rheostat is connected by a lead 35 to one-side of thebattery 33,

the coil ll of the rheostat being connected by a lead 31 to the innercollector ring 2|, said lead 21 being extended into the spindle l3 andout of the same and the sleeve 20 to said ring. The other side of thebattery 33 is similarly connected by a lead 28 to the outer collectorring 22. The

coil units I! or the field are wound in series. The

. brush 3| of the inner collector ring 2| is connected by a lead 39 toone side 0! the field, designated 40, and which has its other sidewired, as at, H, to one of the brushes of the commutator ring IS. Thebrush 32 of the outer collector ring 22 is wired by a lead 42 to theother brush 29 of the commutator ring l9.

As will be understood, when the described field is energized it iscaused to revolve around the armature l8 and to thereby revolve thewheel, and the speed of revolution may be selectively controlled throughthe rheostat 34, 34'.

The-foregoing will, it is believed, sufilce to impart a clearunderstanding of my invention without further explanation.

Manifestly, the invention, as described, is susceptible of modificationwithout departing from the inventive concept, and right is hereinreserved to such modifications as fall within the scope of thesubjoi'ned claims.

What I claim is: I

1. In a landing gear for airplanes, the combination with a hollow fixedwheel spindle, of a wheel rotatably mounted on said spindle andincluding a rim and a back plate forming a circu lar open front chamberin said wheel, an armature fast on said spindle within said chamber,

' a plurality of electromagnetic field units extending from the innerwall of said rim radially of said armature and connected in series, afront cover plate detachably secured to said wheel for closing saidchamber, and means to energize said field units comprising a fixedcommutator ring surrounding the spindle, a pair of fixed collector ringssurrounding said spindle and insulated therefrom and from each other, apair of brush-= es for said pair of collector rings, respectively, a

pair of brushes for said commutator ring, means to mount said brushes onsaid ring for rotation thereby around said rings, and a source ofelectrical energy connected on one side to one of the first-mentionedpair of rings and on its other side to the other ring of thefirst-mentioned pair, the connections extending through said spindle.

2. In a landing gear for airplanes, the combination with a hollow fixedwheel spindle, of a wheel rotatably mounted on said spindle andincluding a rim and a back plate forming a circular open front chamberinsaid wheel, an armature fast on said spindle within said chamber, aplurality of electro-magnetic field units extending from the inner wallof said rim radially of said armature and connected in series, a frontcover plate detachably secured to said wheel for closing said chamber,and means to energize said field units comprising a fixed commutatorring surrounding the spindle, a pair of fixed collector ringssurrounding said spindle and insulated therefrom and from each other, apair of brushes for said pair of collector rings, respectively, a pairof brushes for said commutator ring, means to mount said brushes on saidring for rotation thereby around said rings, and a source of electricalenergy connected on one side to one of I the first-mentioned pair ofrings and on its other side to the other ring of the first-mentionedpair, the connections extending through said spindle, one of the brushesof the first-mentioned pair being wired to one side of said field, theother side of the field being wired to one of the brushes of thesecond-mentioned pair, and'a lead connecting the other brush of thefirst-mentioned pair with the other brush of the second-mentioned pair.PAUL A. DOWNEY.

